Anonymous

IDEDOS: Difference between revisions

From Sinclair Wiki

IDEDOS (view source)

Revision as of 23:04, 12 November 2011

723 bytes removed ,  12 November 2011
→‎Partition Type 0x03 - +3DOS
Line 95: Line 95:


=====Partition Type 0x03 - +3DOS=====
=====Partition Type 0x03 - +3DOS=====
The [[+3e|+3e ROMs]] create partitions of type 0x03 i.e. [[+3DOS]] partitions. The type specific data portion of the Partition Entries for these partitions contain a [[+3DOS#XDPB|+3DOS XDPB (eXtended Disc Parameter Block)]] between 0x0020 to 0x003A and also the +3DOS drive letter to which the partition has been mapped (if any)
The [[+3e|+3e ROMs]] create partitions of type 0x03 i.e. [[+3DOS]] partitions. The type specific data portion of the Partition Entries for these partitions contain an [[+3e#Extended_eXtended_Disk_Parameter_Block|extended version]] of the [[+3DOS#XDPB|+3DOS XDPB]] and also the +3DOS drive letter to which the partition has been mapped (if any)


<pre>
<pre>
Line 101: Line 101:
0x0010 03 SC SC SH EC EC EH LS LS LS LS ?? ?? ?? ?? ??
0x0010 03 SC SC SH EC EC EH LS LS LS LS ?? ?? ?? ?? ??
0x0020 DP DP DP DP DP DP DP DP DP DP DP DP DP DP DP DP
0x0020 DP DP DP DP DP DP DP DP DP DP DP DP DP DP DP DP
0x0030 DP DP DP DP DP DP DP DP DP DP ?? ?? DL ?? ?? ??
0x0030 DP DP DP DP DP DP DP DP DP DP DP DP DL ?? ?? ??


Key:
Key:
DP: +3DOS extended disk parameter block byte
DP: First 28 bytes of the +3e "extended XDPB"
DL: plus3dos drive letter
DL: Plus3dos drive letter (or null)
??: unused
??: Unused
</pre>
</pre>
The eXtended Disk Parameter Block data is ordered as follows
<pre>
0x0020  SPT SPT BSH BLM EXM DSM DSM DRM DRM AL0 AL1 CKS CKS OFF OFF PSH
0x0030  PHM sid tps spt fsn ss  glr glf mms ff
key:
SPT: Records Per Track
BSH: Block Shift: 128 * 2^BSH
BLM: Block Mask: 128 * (BLM + 1)
EXM: Extent Mask
DSM: number of blocks - 1
DRM: number of directory entries - 1
AL0: AL0 directory bitmap
AL1: AL1 directory bitmap
CKS: size of checksum vector
OFF: reserved tracks
PSH: physical sector shift
PHM: sector size
sid: sidedness
tps: number of tracks per side
spt: number of sectors per track
fst: first sector number
ss:  (sector size / 128) - 1
glr: gap length (read/write)
glf: gap length (format)
mms: multitrack/modulation/skip
ff:  freeze flag
</pre>


=====Partition Type 0x04 - CP/M Partition=====
=====Partition Type 0x04 - CP/M Partition=====
Retrieved from ‘https://sinclair.wiki.zxnet.co.uk/wiki/Special:MobileDiff/544’